Vacuum brake



N. H. GILMAN VACUUM BRAKE Feb. 9 1926. 5 1,572,526

Filed March 16, 1.925 2 Sheets-Sheet l www ` A aucune@ 6 2 n, m. m 5 m 1e m W 2 5 N 1 A E lM m @im w M r H. m. Ma N. um .F um mm QQ ||.v\l mM jR n. R w m 9 MNYM R. F u@ m. mm3 fkk ZIM/vento@ Nor/MHH 'mn' i PatentedFeb. 9, 1926.

UNITED STATI-:s PArENrioFFlcE.

yNORMAN H. GILMAN, or INDIANAPOLIS, INDIANA, AssIGNoR To. CARL AND JAMESA. ALLIsoN, Dorner MIAMI, FLORIDA.

. VACUUM amarine.

Tb all whom t may concern.:l j

Be it known that I, NORMAN H. GILMAN,

f a citizen of the United States,'residing at 1 fication.

Indianapolisjn the county of Marion and State of Indiana, have inventedcertain new and useful Improvements in Vacuum Brakes, of which thefollowing is a speci- My said invention relates to a vacuum brake foruse primarily'. in motor vehicles and it is an object of the same toprovide' an effective brake of this character which shall be controlledelectrically through intervention ofthe operator of the vehicle.

Another object of the invention is to provide a vacuum brake which shallhave provision for service and emergency application the force of theapplication varying according tothe need ofthe occasion.

von the steering wheel; v

Figure3, a section of thefcylinder and piston of the vacuum mechanismand certain details connected therewith, and

Figure 4, a section at right angles to `Figure 3.

`In the drawings reference character 10 indicates the manifold of anautomobile having a brake rod 11 .which may be connected in vanyconventional or desirable manner to the brakes for the wheels. A

`. spring 12 normally moves the rod inthe direction to release thebrakes, the spring being connected at one end lto a fixed part of themachine frame and at the other end to the rod 11 either vdirectly orthrough intermediate parts. I i

nThe vrod 11 is connected preferably,

through *the intermediary efv a foot lever, providing for manualoperation of the brakes, to a piston rod 13 rigidly secured to 'a piston14 mounted'tb move in a cylinder 15. The piston' is provided withpacklng 16 secured thereto in any desirable manner and a gland 17prevents the entrance of air at the rear side of the iston. In theembodiment'of the inventlon here illustrated the heads/18 and 19 ofthevcylinder are re- Application flied March 16, '1925.- serial N0.1s,o33.

movably secured together by bolts'20, said G. FISHERI y ends beingseparated by thecylindrical element 15.

The cylindernl head 19 has an extension which is here shown asrelatively long and narrow'and is provided midway of its lenjh with yacylindrical recess having rigi secured therein, between its ends, acollar 21 which may be formed as an integral flange, i

if desired. A valve 22 isv slidably located below/the collar 21 and isguided'bya pin 23 in a manner to prevent rotation in the recess whichacts as a cylinder therefor'. Another piston is located at 24y above thecollar and these pistons are connected by means of a screw 25 in acentrally threaded boss on the piston 24 and a spring 26'se# cured, atone end to a boss on the piston 22 and at the other end tothe adjacentend of the screw 25. A spring 27 is interposed between the upper endof-the skirt of valve 22 and the collar 21. Thisl provides for yieldingmovement of eithenpiston by the other and it will be evident that thepiston 24, if moved upward, will draw the valve 22 after it, suchmovement being limited by the collar 21 andl yieldingly limited by thespring 27 which, however, is weaker than sprlng 26.

`The extension is also provided at each side of the central opening withsmaller openings in which valves `28 and 29 are mounted to reciprocate.VThesenpenings are enlarged at 'the lower end to receive the valveswhich have stems 3Q and taperedy yshoulders fitting againstcorrespondingly tapered seats 31. The stems. have longitudinal groovesabove the shoulders to provide airrpassages when the valves are opened.Armatures 32 are attached to the valve stems at their upper ends andelectromagnets 33 and 34 are provided for opening the respective valvesYagainst the tension of springs 28 and129 TheseA-electromagnets comprisef coils supported about intgral posts V35 co-axial with upwardly openingrecesses .in the extensionl on the. head 19) and these recesses as wellas the] central recess are closed by a cap plate 36. Al screw 37 engagesla threaded opening atthecenter of4 `thecapplate and provides adjustablemeans for limiting the travel of the pistonA 24;.` A lock nut 38 servesto lhold the screw CAI nut. 46 for receiving Athe wire 42 which may nut48 which be connected thereto by solder or otherwise. An emergency wire47` connects the electro, magnet 34 to the push button and this wirevmay be soldered or otherwise attached' to.a has' an opening at 49 forthe wire. v

The means for securing the push button tothe steering wheel .comprisesya threaded socketOin which the push button is mounted for up and downsliding movement. A spring 51 serves to hold it normally in itsuppermost position'. The `spring bears at its lower end upon a hollowcylindrical block 52 of insulating material mounted centrally of thesocket which hasea shoulder at* its upper end to limit the xupwardmovement of a block 53 supported by a compression spring 54 resting atits lower` end on the head of a screw 55 on which the nut 46 isthreaded. The screw 55 1s supported in position on the socket 5() by avsocket 5,6 having an outwardly extending flange at its upper end restingon a ring 57 of insulating material which in turn vrests on an inwardlyAextending flange on the socket 50. Atits lower end the socket 56 has aninwardly extending flange supporting a ring 58 of insulating materialand tle head of. the screw rests on the latter ring while the nut 46 issbp-ported from the lower end of the' socket56 by an insulating so astopull/"down its armature 32 an washer/59.

c The nut 48 is threaded on the lower end of socket^56 to' hold it inplace, the nut being supported from. the socket 50 by an insulatingwasher 60. The cylindrical member 52 rests atr its lower end on the headof screw 55. The push button 43 is provided -with a downwardly extendingcentrahboss 61 which serves 'to guide and support springv 51- and alsoto close a circuit through the service wire 42, nut 46, screw 55, spring54, block v53., pnsh button 43 and socket 50 which is grounded on thesteering wheel. The connection of the service wire to the electromagnet33 and by wire 41 to battery 39 causes the coil of the electromagnettobe ener iled epess the valve 31 to open a passage from theair chamberbelow the valve as hereinafter described. i 1

Further depression of the push button closes a circuit through emergencywire 47, nut 48, socket 56, the depending flange 63 of the push buttonand the socket 5 0 tov ground on the steering wheel. The connec-` tionof wire 47y at the other en'd of the coil lof electromagnet 34fand thebattery 39 ener- 1,572,52e f f gizes the electromagnet tol pull down itsarmature and open the-right-hand valve 31 for purposes hereinafterdescribed.

The means for creating a suction on the piston 14 to epull on theconnecting rod 13 and apply the brakes against the tension of the spring12 includes a pipe 64 connected at' one end to the intake manifold 10and at the other end having a threaded connection at 65 to the upwardextension of the cylinder head 19. A passage 66 leads from the threadedopening 65 to ports 67 and 68 opening into the chambers below therespective valves 28 and 29. A passage 69 above the valve 28 leads to aport- 70 opening into the central recess of the extension' on head 19near the outer end thereof. Another port 73 leads from the passage 66-into the central chamber adjacent the lower end thereof. f A shortpassage 74 leads through the head 19 tofthe central chamber and a. port75 opens directly through the head into said chamber. The valve 22 has aport 76 at one side registering with passage 74 for equaliz-` ing thepressure between the pistons and in the cylinder 15 when the passage 74registers with port 76. .A port 77 in the piston 'I 24 provides meansfor equalizing the pressure in thespace at the upper part of thecylinder and inthe space between the pistons. Y f 1 l In the operationof myAyr device a service application is made, as previously indicated,

by depressing the push button sufliciently to create a vacuum 1nthechamber above the piston 24 thus drawing the piston upward in saidchamber. The upward limitof the movement of the pis'ton is indicated bythe port 70 asthe suction'is cut of when this port is closed by theskirt of the piston. As the piston 24 moves upit drags after it thevalve 22 by means of the spring 26, the rate The connection from theinand extent of upward movement of the valve .22 being determined by thedifference in strength of the springs 26 `and 27. The upward movementofthe valve l2 2 uncovers port 73 andestablishes communicationbetweensaid port and port 7 5 whereupon the suction from the intakemanifold exhausts the air in the cylinder 15 and moves the'piston 14with consequent relatively slow' application of/ the brakes:

Further depression of the push button closes not only the circuitthrough the serv'- ice wire but also the circuit through the emergencywire 4 7, as above explained, whereupon the valve 29v is also moved toopen the passage 71. The suction from the intake manifold now operatesvnot only through the passages described in connectionl with the service'application but also acts through port` 73, passage 6 6, port 68,passage 71 and portf72 to draw the piston 24 to the extreme upper end ofits chamber or so far as permitted by the screw 37. #This movesthepiston 22 Ito its extreme upward y position opening the passage 74 aswell as the port 75 and' permitting the suction of the intakemanifoldtto exhaust the air sud-1 denly from the cylinder thereby'making an emergency application of the brakes.

` 'When the push button is released to break the circuitsthe'electromagnets are de-enr-e gized, closing the valve 28 or bothvalves 28 and 291as/the case may be and cutting olf ,the suctionin thechamber above the piston 24.

l N This permits the piston 24 tp begin its downthe brakingelfortrequired and the vsize of ating on piston 14 and the controlling pistonward movement under the impetus of the spring 27 which actionIisfacilitated by entrance of air' through a port 78 which connects Witha pipe 79 opening 'at its other end into the cylinder at 80. Connectionis made" to the cylinder so as to avcid ventrance of' dirt into thecylinder 15 and connected parts from the outer air and so as to balancethe pressure at opposite sides of the piston, 14.

'Ihe air from the cylinder passesthrough the i port 77 into the upperchamber to break the vacuum and as soon as the valvev 22 has moved downfar enough tocause theport 76 to register Iwith passageA 4 itY alsobreaks the vacuum in the cylinder e 5, thereby facili'- tating the brakereleasing action of'the spring 12. v

It will be plain vto anyone familiar with vacuum operated brakes'thatthere can be a variation 1n vacuum of from zero to ashigh as 13lb's.,depending on the position of the v carbureter throttle and the`speed of the engine pistons. The proper vacuum required for servicebrake operation depends -upon piston 14 and its leverage.

In the device. illustrated about 2 pounds per square inch vacuum isrequired. There' tending to pull valve 22 upward is on Fthe under sideof 22 tending to pull downward. This 2 lbs. pressure is thus maintamed'by this balanced condition and communicatedl through erts 74and 75 tooperate piston 14. It-wil be obvious to those skilled in the art thatvarious changes may befmade `in my'- hausting the air over the piston, aplurality 130 device without departin from the spirit of the invention'and there ore"I do not limit myselfI to what is shown in the-drawingsand describled inthe specification` but only Y as indicated in theappended claims. .a

Having thus fully described my said'inl vention, what I claimas new anddesire to secureby Letters Patent, is z uum operating means therefonconnected to the intake manifold, electrical controlling jmeans or theoperating means including a circuit closer, and connections forvmanually actuating the circuit closer ,to 'cause'either service \or'emergency application of thebraking means, substantlally as set forth.

1. .In an automobile, braking means, vac- 2. In an automobile, brakingmeans, vac-v Y `umn operating means therefor connected to theYintakenanifold, electrical controlling means for the'operating meansincluding a push button `on the `steering wheel, means for 'l causing aservice application o fpthe brakes y by depression of the push button,and means for causing an emergenc application by further depressionthereo set forth.

K, substantially as Ina vehicle, a brake, suction actuating operatingmeans therefor including a p-lurality of air-passages, a valve in eachpas i sage, andpmeans for. opening said valve si'- multaneously for'n anemergency operation or Ja smgle valvefor a servlce operation,

substantially as set forth.`

4f A braking mechanism as in claimy inl clucl'ing an. electromagnet foreach valve, normally open circuits vfor said'electromagp nets, and meansfor closing each of the circuits .foran emergency operation or a sin le`circuit for a servlce operation, substantiallyA f as set forth.

5. In a motor vehicle, braking means, a .'piston connected thereto, apipe leading from the intake side of the motor for exhausting th'eairover the piston, a plurality of passages leadin from said pipe throughthe .cylinder hea a valve normally closing said assav'es and meansl forliftin said valve R b a to varying heights for opening therespectiveassages, substantially as set forth.

6. n a motor vehicle, braking means, a Apiston connected thereto,l apipe leading from' the `intake side of the motor forex-y hausting theair over the piston, a plurality of passages leading from said pipethrough the cylinder head, a valvel normally closing said passages, andconnections from, said pipe for lifting said valve, substantially asVfset forth.

lwith electrical controllin means for. said liftin means, substantial gas Set forth.

8. nv a motor vehicle, r

from the intake side of the motor for exv7. A braking' mechanism sinclaim ej akingn'means, a `piston connected thereto, 'a pipe leading,piston connected thereto, a, pipe leading from the intake side of themotor for exhausting the air over the-piston, a plurality of passagesleading from said pipe through the cylinder head, a valve normallyclosing said passages, a'piston for liftingsaid valve, a vacuum chamberat one side of the piston, independent passages from said pipe to saidchamber openin thereinto at dierent heights, means for selectivelycontrolling said passages including normally-'closed valves in saidpassages, and manually con- 'trolled' electrical means for opening the vvalves, substantiallyas set forth.

10. Ina motor vehicle, braking means, a piston connected thereto, a pipeleading from the intake side of the motor; for ex- 7 hausting the airover the piston, a plurality of passages leading from said pipe throughthe cylinder head, a valve normally closing said passages, a piston forlifting said valve, a vacuum chamber at one side of the piston,independent passages from said pipe to said chamber openin thereinto atdifferent heights, means or selectively controlling said passagesincluding normally-closed valves in said passages, manually controlledelectrical means for opening the valves, and yielding .connectionsbetween said -firstnamed-valve and the piston actuated thereby,substantially as set forth.

11. In a motorvehicle, braking means, a piston connected thereto, a pipeleading from the intake vsideof the motor for exhaust-ing the air overthe piston, a plurality of passages leading from said-pipe through thecylinder head, a valve normally closing said passages, a piston forlifting said valve, a vacuum chamber at one side of ,the piston,independent passages from said pipe to said chamber opening thereinto atdifferent heights, means for selectively controlling named valve andthepiston actuated thereby, and means for yieldingly opposing themovement of the last-named piston with its operatingvalve, substantiallyas set forth. 4 12. In a -motor vehicle, braking means, a pistonconnected thereto, a pipe leading from thel intake side ofthe motor foreX- hausting the air over the piston, a plurality of passages leadingfrom said pipe through the cylinder head, a valve normally closing saidpassages, a piston for lifting said valve, a vacuum chamber at one sideof the piston, independent passages from said-pipe to'said chamberopening thereinto at different heights, means for selectivelycontrolling said passages including normally-closed valves in saidpassages, manually controlled electrical means for opening the valves,and means for adjustably limiting 'the movement of said first-namedvalve, substantially as set forth.

n13. A braking mechanism as in claim 2, with independent circuits forsaid brake applications, and independent resilient means for breakingthe respective circuits, substantially as set forth.

14. In a motor vehicle, braking means, vacuum actuated operating meanstherefor including a brake cylinder, a piston in said cylinder adaptedto be operated by suction from .the intake manifold for applying'thebrakes, an auxiliary cylinder having communication with said firstmentionedcylinder adapted for applying the actuating medium gradually orrapidly to said cylinder, and a communicating passage between the remoteends of said cylinders for establishing a'balance of pressure in` saidcylinders, substantially as set forth. 2

In Witnesswhereof, I have hereunto set my hand and seal at Indianapolis,Indiana,

this' 28th day-of February, A. D. nineteen hundred and twenty-tive.

- NORMAN H. GmMAN. [1.. 8.] l

